Proxy access to a dispersed storage network

ABSTRACT

A method begins with a processing module selecting one of a plurality of dispersed storage (DS) processing modules for facilitating access to a dispersed storage network (DSN) memory. The method continues with the processing module sending a DSN memory access request to the one of the plurality of DS processing modules. The method continues with the processing module selecting another one of the plurality of DS processing modules when no response is received within a given time frame or when the response to the access request does not include an access indication. The method continues with the processing module sending the DSN memory access request to the another one of the plurality of DS processing modules.

CROSS REFERENCE TO RELATED PATENTS

The present U.S. Utility Patent Application claims priority pursuant to35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/264,297,entitled “DISTRIBUTED STORAGE NETWORK COMMUNICATIONS METHOD,” (AttorneyDocket No. CS285), filed Nov. 25, 2009, pending, which is herebyincorporated herein by reference in its entirety and made part of thepresent U.S. Utility Patent Application for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

NOT APPLICABLE

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

NOT APPLICABLE

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention relates generally to computing systems and moreparticularly to data storage solutions within such computing systems.

2. Description of Related Art

Computers are known to communicate, process, and store data. Suchcomputers range from wireless smart phones to data centers that supportmillions of web searches, stock trades, or on-line purchases every day.In general, a computing system generates data and/or manipulates datafrom one form into another. For instance, an image sensor of thecomputing system generates raw picture data and, using an imagecompression program (e.g., JPEG, MPEG, etc.), the computing systemmanipulates the raw picture data into a standardized compressed image.

With continued advances in processing speed and communication speed,computers are capable of processing real time multimedia data forapplications ranging from simple voice communications to streaming highdefinition video. As such, general-purpose information appliances arereplacing purpose-built communications devices (e.g., a telephone). Forexample, smart phones can support telephony communications but they arealso capable of text messaging and accessing the internet to performfunctions including email, web browsing, remote applications access, andmedia communications (e.g., telephony voice, image transfer, musicfiles, video files, real time video streaming. etc.).

Each type of computer is constructed and operates in accordance with oneor more communication, processing, and storage standards. As a result ofstandardization and with advances in technology, more and moreinformation content is being converted into digital formats. Forexample, more digital cameras are now being sold than film cameras, thusproducing more digital pictures. As another example, web-basedprogramming is becoming an alternative to over the air televisionbroadcasts and/or cable broadcasts. As further examples, papers, books,video entertainment, home video, etc. are now being stored digitally,which increases the demand on the storage function of computers.

A typical computer storage system includes one or more memory devicesaligned with the needs of the various operational aspects of thecomputer's processing and communication functions. Generally, theimmediacy of access dictates what type of memory device is used. Forexample, random access memory (RAM) memory can be accessed in any randomorder with a constant response time, thus it is typically used for cachememory and main memory. By contrast, memory device technologies thatrequire physical movement such as magnetic disks, tapes, and opticaldiscs, have a variable response time as the physical movement can takelonger than the data transfer, thus they are typically used forsecondary memory (e.g., hard drive, backup memory, etc.).

A computer's storage system will be compliant with one or more computerstorage standards that include, but are not limited to, network filesystem (NFS), flash file system (FFS), disk file system (DFS), smallcomputer system interface (SCSI), internet small computer systeminterface (iSCSI), file transfer protocol (FTP), and web-baseddistributed authoring and versioning (WebDAV). These standards specifythe data storage format (e.g., files, data objects, data blocks,directories, etc.) and interfacing between the computer's processingfunction and its storage system, which is a primary function of thecomputer's memory controller.

Despite the standardization of the computer and its storage system,memory devices fail; especially commercial grade memory devices thatutilize technologies incorporating physical movement (e.g., a discdrive). For example, it is fairly common for a disc drive to routinelysuffer from bit level corruption and to completely fail after threeyears of use. One solution is to a higher-grade disc drive, which addssignificant cost to a computer.

Another solution is to utilize multiple levels of redundant disc drivesto replicate the data into two or more copies. One such redundant driveapproach is called redundant array of independent discs (RAID). In aRAID device, a RAID controller adds parity data to the original databefore storing it across the array. The parity data is calculated fromthe original data such that the failure of a disc will not result in theloss of the original data. For example, RAID 5 uses three discs toprotect data from the failure of a single disc. The parity data, andassociated redundancy overhead data, reduces the storage capacity ofthree independent discs by one third (e.g., n-1=capacity). RAID 6 canrecover from a loss of two discs and requires a minimum of four discswith a storage capacity of n-2.

While RAID addresses the memory device failure issue, it is not withoutits own failures issues that affect its effectiveness, efficiency andsecurity. For instance, as more discs are added to the array, theprobability of a disc failure increases, which increases the demand formaintenance. For example, when a disc fails, it needs to be manuallyreplaced before another disc fails and the data stored in the RAIDdevice is lost. To reduce the risk of data loss, data on a RAID deviceis typically copied on to one or more other RAID devices. While thisaddresses the loss of data issue, it raises a security issue sincemultiple copies of data are available, which increases the chances ofunauthorized access. Further, as the amount of data being stored grows,the overhead of RAID devices becomes a non-trivial efficiency issue.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic block diagram of an embodiment of a computingsystem in accordance with the invention;

FIG. 2 is a schematic block diagram of an embodiment of a computing corein accordance with the invention;

FIG. 3 is a schematic block diagram of an embodiment of a distributedstorage processing unit in accordance with the invention;

FIG. 4 is a schematic block diagram of an embodiment of a grid module inaccordance with the invention;

FIG. 5 is a diagram of an example embodiment of error coded data slicecreation in accordance with the invention;

FIG. 6 is a schematic block diagram of another embodiment of a computingsystem in accordance with the invention;

FIG. 7 is a flowchart illustrating an example of accessing a dispersedstorage network (DSN) memory in accordance with the invention;

FIG. 8 is a flowchart illustrating an example of determining an activemaster dispersed storage (DS) processing unit in accordance with theinvention;

FIG. 9 is a flowchart illustrating an example of processing a dispersedstorage network (DSN) memory access request in accordance with theinvention;

FIG. 10 is a flowchart illustrating an example of establishing aconnection with a dispersed storage (DS) unit in accordance with theinvention;

FIG. 11 is a flowchart illustrating an example of establishing a secureconnection in accordance with the invention;

FIG. 12 is a flowchart illustrating an example of detecting a filechange in accordance with the invention;

FIG. 13 is a flowchart illustrating an example of backing up a dataobject in accordance with the invention;

FIG. 14 is a flowchart illustrating an example of cataloging ofdispersed storage network (DSN) memory content in accordance with theinvention; and

FIG. 15 is a flowchart illustrating an example of searching dispersedstorage network (DSN) memory content in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram of a computing system 10 thatincludes one or more of a first type of user devices 12, one or more ofa second type of user devices 14, at least one distributed storage (DS)processing unit 16, at least one DS managing unit 18, at least onestorage integrity processing unit 20, and a distributed storage network(DSN) memory 22 coupled via a network 24. The network 24 may include oneor more wireless and/or wire lined communication systems; one or moreprivate intranet systems and/or public internet systems; and/or one ormore local area networks (LAN) and/or wide area networks (WAN).

The DSN memory 22 includes a plurality of distributed storage (DS) units36 for storing data of the system. Each of the DS units 36 includes aprocessing module and memory and may be located at a geographicallydifferent site than the other DS units (e.g., one in Chicago, one inMilwaukee, etc.). The processing module may be a single processingdevice or a plurality of processing devices. Such a processing devicemay be a microprocessor, micro-controller, digital signal processor,microcomputer, central processing unit, field programmable gate array,programmable logic device, state machine, logic circuitry, analogcircuitry, digital circuitry, and/or any device that manipulates signals(analog and/or digital) based on hard coding of the circuitry and/oroperational instructions. The processing module may have an associatedmemory and/or memory element, which may be a single memory device, aplurality of memory devices, and/or embedded circuitry of the processingmodule. Such a memory device may be a read-only memory, random accessmemory, volatile memory, non-volatile memory, static memory, dynamicmemory, flash memory, cache memory, and/or any device that storesdigital information. Note that if the processing module includes morethan one processing device, the processing devices may be centrallylocated (e.g., directly coupled together via a wired and/or wireless busstructure) or may be distributedly located (e.g., cloud computing viaindirect coupling via a local area network and/or a wide area network).Further note that when the processing module implements one or more ofits functions via a state machine, analog circuitry, digital circuitry,and/or logic circuitry, the memory and/or memory element storing thecorresponding operational instructions may be embedded within, orexternal to, the circuitry comprising the state machine, analogcircuitry, digital circuitry, and/or logic circuitry. Still further notethat, the memory element stores, and the processing module executes,hard coded and/or operational instructions corresponding to at leastsome of the steps and/or functions illustrated in FIGS. 1-15.

Each of the user devices 12-14, the DS processing unit 16, the DSmanaging unit 18, and the storage integrity processing unit 20 may be aportable computing device (e.g., a social networking device, a gamingdevice, a cell phone, a smart phone, a personal digital assistant, adigital music player, a digital video player, a laptop computer, ahandheld computer, a video game controller, and/or any other portabledevice that includes a computing core) and/or a fixed computing device(e.g., a personal computer, a computer server, a cable set-top box, asatellite receiver, a television set, a printer, a fax machine, homeentertainment equipment, a video game console, and/or any type of homeor office computing equipment). Such a portable or fixed computingdevice includes a computing core 26 and one or more interfaces 30, 32,and/or 33. An embodiment of the computing core 26 will be described withreference to FIG. 2.

With respect to the interfaces, each of the interfaces 30, 32, and 33includes software and/or hardware to support one or more communicationlinks via the network 24 and/or directly. For example, interfaces 30support a communication link (wired, wireless, direct, via a LAN, viathe network 24, etc.) between the first type of user device 14 and theDS processing unit 16. As another example, DSN interface 32 supports aplurality of communication links via the network 24 between the DSNmemory 22 and the DS processing unit 16, the first type of user device12, and/or the storage integrity processing unit 20. As yet anotherexample, interface 33 supports a communication link between the DSmanaging unit 18 and any one of the other devices and/or units 12, 14,16, 20, and/or 22 via the network 24.

In general and with respect to data storage, the system 10 supportsthree primary functions: distributed network data storage management,distributed data storage and retrieval, and data storage integrityverification. In accordance with these three primary functions, data canbe distributedly stored in a plurality of physically different locationsand subsequently retrieved in a reliable and secure manner regardless offailures of individual storage devices, failures of network equipment,the duration of storage, the amount of data being stored, attempts athacking the data, etc.

The DS managing unit 18 performs distributed network data storagemanagement functions, which include establishing distributed datastorage parameters, performing network operations, performing networkadministration, and/or performing network maintenance. The DS managingunit 18 establishes the distributed data storage parameters (e.g.,allocation of virtual DSN memory space, distributed storage parameters,security parameters, billing information, user profile information,etc.) for one or more of the user devices 12-14 (e.g., established forindividual devices, established for a user group of devices, establishedfor public access by the user devices, etc.). For example, the DSmanaging unit 18 coordinates the creation of a vault (e.g., a virtualmemory block) within the DSN memory 22 for a user device (for a group ofdevices, or for public access). The DS managing unit 18 also determinesthe distributed data storage parameters for the vault. In particular,the DS managing unit 18 determines a number of slices (e.g., the numberthat a data segment of a data file and/or data block is partitioned intofor distributed storage) and a read threshold value (e.g., the minimumnumber of slices required to reconstruct the data segment).

As another example, the DS managing module 18 creates and stores,locally or within the DSN memory 22, user profile information. The userprofile information includes one or more of authentication information,permissions, and/or the security parameters. The security parameters mayinclude one or more of encryption/decryption scheme, one or moreencryption keys, key generation scheme, and data encoding/decodingscheme.

As yet another example, the DS managing unit 18 creates billinginformation for a particular user, user group, vault access, publicvault access, etc. For instance, the DS managing unit 18 tracks thenumber of times user accesses a private vault and/or public vaults,which can be used to generate a per-access bill. In another instance,the DS managing unit 18 tracks the amount of data stored and/orretrieved by a user device and/or a user group, which can be used togenerate a per-data-amount bill.

The DS managing unit 18 also performs network operations, networkadministration, and/or network maintenance. As at least part ofperforming the network operations and/or administration, the DS managingunit 18 monitors performance of the devices and/or units of the system10 for potential failures, determines the devices and/or unit'sactivation status, determines the devices' and/or units' loading, andany other system level operation that affects the performance level ofthe system 10. For example, the DS managing unit 18 receives andaggregates network management alarms, alerts, errors, statusinformation, performance information, and messages from the devices12-14 and/or the units 16, 20, 22. For example, the DS managing unit 18receives a simple network management protocol (SNMP) message regardingthe status of the DS processing unit 16.

The DS managing unit 18 performs the network maintenance by identifyingequipment within the system 10 that needs replacing, upgrading,repairing, and/or expanding. For example, the DS managing unit 18determines that the DSN memory 22 needs more DS units 36 or that one ormore of the DS units 36 needs updating.

The second primary function (i.e., distributed data storage andretrieval) begins and ends with a user device 12-14. For instance, if asecond type of user device 14 has a data file 38 and/or data block 40 tostore in the DSN memory 22, it send the data file 38 and/or data block40 to the DS processing unit 16 via its interface 30. As will bedescribed in greater detail with reference to FIG. 2, the interface 30functions to mimic a conventional operating system (OS) file systeminterface (e.g., network file system (NFS), flash file system (FFS),disk file system (DFS), file transfer protocol (FTP), web-baseddistributed authoring and versioning (WebDAV), etc.) and/or a blockmemory interface (e.g., small computer system interface (SCSI), internetsmall computer system interface (iSCSI), etc.). In addition, theinterface 30 may attach a user identification code (ID) to the data file38 and/or data block 40.

The DS processing unit 16 receives the data file 38 and/or data block 40via its interface 30 and performs a distributed storage (DS) process 34thereon (e.g., an error coding dispersal storage function). The DSprocessing 34 begins by partitioning the data file 38 and/or data block40 into one or more data segments, which is represented as Y datasegments. For example, the DS processing 34 may partition the data file38 and/or data block 40 into a fixed byte size segment (e.g., 2¹ to 2^(n) bytes, where n=>2) or a variable byte size (e.g., change byte sizefrom segment to segment, or from groups of segments to groups ofsegments, etc.).

For each of the Y data segments, the DS processing 34 error encodes(e.g., forward error correction (FEC), information dispersal algorithm,or error correction coding) and slices (or slices then error encodes)the data segment into a plurality of error coded (EC) data slices 42-48,which is represented as X slices per data segment. The number of slices(X) per segment, which corresponds to a number of pillars n, is set inaccordance with the distributed data storage parameters and the errorcoding scheme. For example, if a Reed-Solomon (or other FEC scheme) isused in an n/k system, then a data segment is divided into n slices,where k number of slices is needed to reconstruct the original data(i.e., k is the threshold). As a few specific examples, the n/k factormay be 5/3; 6/4; 8/6; 8/5; 16/10.

For each slice 42-48, the DS processing unit 16 creates a unique slicename and appends it to the corresponding slice 42-48. The slice nameincludes universal DSN memory addressing routing information (e.g.,virtual memory addresses in the DSN memory 22) and user-specificinformation (e.g., user ID, file name, data block identifier, etc.).

The DS processing unit 16 transmits the plurality of EC slices 42-48 toa plurality of DS units 36 of the DSN memory 22 via the DSN interface 32and the network 24. The DSN interface 32 formats each of the slices fortransmission via the network 24. For example, the DSN interface 32 mayutilize an internet protocol (e.g., TCP/IP, etc.) to packetize theslices 42-48 for transmission via the network 24.

The number of DS units 36 receiving the slices 42-48 is dependent on thedistributed data storage parameters established by the DS managing unit18. For example, the DS managing unit 18 may indicate that each slice isto be stored in a different DS unit 36. As another example, the DSmanaging unit 18 may indicate that like slice numbers of different datasegments are to be stored in the same DS unit 36. For example, the firstslice of each of the data segments is to be stored in a first DS unit36, the second slice of each of the data segments is to be stored in asecond DS unit 36, etc. In this manner, the data is encoded anddistributedly stored at physically diverse locations to improved datastorage integrity and security. Further examples of encoding the datasegments will be provided with reference to one or more of FIGS. 2-15.

Each DS unit 36 that receives a slice 42-48 for storage translates thevirtual DSN memory address of the slice into a local physical addressfor storage. Accordingly, each DS unit 36 maintains a virtual tophysical memory mapping to assist in the storage and retrieval of data.

The first type of user device 12 performs a similar function to storedata in the DSN memory 22 with the exception that it includes the DSprocessing. As such, the device 12 encodes and slices the data fileand/or data block it has to store. The device then transmits the slices11 to the DSN memory via its DSN interface 32 and the network 24.

For a second type of user device 14 to retrieve a data file or datablock from memory, it issues a read command via its interface 30 to theDS processing unit 16. The DS processing unit 16 performs the DSprocessing 34 to identify the DS units 36 storing the slices of the datafile and/or data block based on the read command. The DS processing unit16 may also communicate with the DS managing unit 18 to verify that theuser device 14 is authorized to access the requested data.

Assuming that the user device is authorized to access the requesteddata, the DS processing unit 16 issues slice read commands to at least athreshold number of the DS units 36 storing the requested data (e.g., toat least 10 DS units for a 16/10 error coding scheme). Each of the DSunits 36 receiving the slice read command, verifies the command,accesses its virtual to physical memory mapping, retrieves the requestedslice, or slices, and transmits it to the DS processing unit 16.

Once the DS processing unit 16 has received a read threshold number ofslices for a data segment, it performs an error decoding function andde-slicing to reconstruct the data segment. When Y number of datasegments has been reconstructed, the DS processing unit 16 provides thedata file 38 and/or data block 40 to the user device 14. Note that thefirst type of user device 12 performs a similar process to retrieve adata file and/or data block.

The storage integrity processing unit 20 performs the third primaryfunction of data storage integrity verification. In general, the storageintegrity processing unit 20 periodically retrieves slices 45, and/orslice names, of a data file or data block of a user device to verifythat one or more slices have not been corrupted or lost (e.g., the DSunit failed). The retrieval process mimics the read process previouslydescribed.

If the storage integrity processing unit 20 determines that one or moreslices is corrupted or lost, it rebuilds the corrupted or lost slice(s)in accordance with the error coding scheme. The storage integrityprocessing unit 20 stores the rebuild slice, or slices, in theappropriate DS unit(s) 36 in a manner that mimics the write processpreviously described.

FIG. 2 is a schematic block diagram of an embodiment of a computing core26 that includes a processing module 50, a memory controller 52, mainmemory 54, a video graphics processing unit 55, an input/output (IO)controller 56, a peripheral component interconnect (PCI) interface 58,at least one IO device interface module 62, a read only memory (ROM)basic input output system (BIOS) 64, and one or more memory interfacemodules. The memory interface module(s) includes one or more of auniversal serial bus (USB) interface module 66, a host bus adapter (HBA)interface module 68, a network interface module 70, a flash interfacemodule 72, a hard drive interface module 74, and a DSN interface module76. Note the DSN interface module 76 and/or the network interface module70 may function as the interface 30 of the user device 14 of FIG. 1.Further note that the IO device interface module 62 and/or the memoryinterface modules may be collectively or individually referred to as IOports.

The processing module 50 may be a single processing device or aplurality of processing devices. Such a processing device may be amicroprocessor, micro-controller, digital signal processor,microcomputer, central processing unit, field programmable gate array,programmable logic device, state machine, logic circuitry, analogcircuitry, digital circuitry, and/or any device that manipulates signals(analog and/or digital) based on hard coding of the circuitry and/oroperational instructions. The processing module 50 may have anassociated memory and/or memory element, which may be a single memorydevice, a plurality of memory devices, and/or embedded circuitry of theprocessing module 50. Such a memory device may be a read-only memory,random access memory, volatile memory, non-volatile memory, staticmemory, dynamic memory, flash memory, cache memory, and/or any devicethat stores digital information. Note that if the processing module 50includes more than one processing device, the processing devices may becentrally located (e.g., directly coupled together via a wired and/orwireless bus structure) or may be distributedly located (e.g., cloudcomputing via indirect coupling via a local area network and/or a widearea network). Further note that when the processing module 50implements one or more of its functions via a state machine, analogcircuitry, digital circuitry, and/or logic circuitry, the memory and/ormemory element storing the corresponding operational instructions may beembedded within, or external to, the circuitry comprising the statemachine, analog circuitry, digital circuitry, and/or logic circuitry.Still further note that, the memory element stores, and the processingmodule 50 executes, hard coded and/or operational instructionscorresponding to at least some of the steps and/or functions illustratedin FIGS. 1-15.

FIG. 3 is a schematic block diagram of an embodiment of a dispersedstorage (DS) processing module 34 of user device 12 and/or of the DSprocessing unit 16. The DS processing module 34 includes a gatewaymodule 78, an access module 80, a grid module 82, and a storage module84. The DS processing module 34 may also include an interface 30 and theDSnet interface 32 or the interfaces 68 and/or 70 may be part of user 12or of the DS processing unit 14. The DS processing module 34 may furtherinclude a bypass/feedback path between the storage module 84 to thegateway module 78. Note that the modules 78-84 of the DS processingmodule 34 may be in a single unit or distributed across multiple units.

In an example of storing data, the gateway module 78 receives anincoming data object that includes a user ID field 86, an object namefield 88, and the data field 40 and may also receive correspondinginformation that includes a process identifier (e.g., an internalprocess/application ID), metadata, a file system directory, a blocknumber, a transaction message, a user device identity (ID), a dataobject identifier, a source name, and/or user information. The gatewaymodule 78 authenticates the user associated with the data object byverifying the user ID 86 with the managing unit 18 and/or anotherauthenticating unit.

When the user is authenticated, the gateway module 78 obtains userinformation from the management unit 18, the user device, and/or theother authenticating unit. The user information includes a vaultidentifier, operational parameters, and user attributes (e.g., userdata, billing information, etc.). A vault identifier identifies a vault,which is a virtual memory space that maps to a set of DS storage units36. For example, vault 1 (i.e., user 1's DSN memory space) includeseight DS storage units (X=8 wide) and vault 2 (i.e., user 2's DSN memoryspace) includes sixteen DS storage units (X=16 wide). The operationalparameters may include an error coding algorithm, the width n (number ofpillars X or slices per segment for this vault), a read threshold T, awrite threshold, an encryption algorithm, a slicing parameter, acompression algorithm, an integrity check method, caching settings,parallelism settings, and/or other parameters that may be used to accessthe DSN memory layer.

The gateway module 78 uses the user information to assign a source name35 to the data. For instance, the gateway module 60 determines thesource name 35 of the data object 40 based on the vault identifier andthe data object. For example, the source name may contain a fileidentifier (ID), a vault generation number, a reserved field, and avault identifier (ID). As another example, the gateway module 78 maygenerate the file ID based on a hash function of the data object 40.Note that the gateway module 78 may also perform message conversion,protocol conversion, electrical conversion, optical conversion, accesscontrol, user identification, user information retrieval, trafficmonitoring, statistics generation, configuration, management, and/orsource name determination.

The access module 80 receives the data object 40 and creates a series ofdata segments 1 through Y 90-92 in accordance with a data storageprotocol (e.g., file storage system, a block storage system, and/or anaggregated block storage system). The number of segments Y may be chosenor randomly assigned based on a selected segment size and the size ofthe data object. For example, if the number of segments is chosen to bea fixed number, then the size of the segments varies as a function ofthe size of the data object. For instance, if the data object is animage file of 4,194,304 eight bit bytes (e.g., 33,554,432 bits) and thenumber of segments Y=131,072, then each segment is 256 bits or 32 bytes.As another example, if segment sized is fixed, then the number ofsegments Y varies based on the size of data object. For instance, if thedata object is an image file of 4,194,304 bytes and the fixed size ofeach segment is 4,096 bytes, the then number of segments Y=1,024. Notethat each segment is associated with the same source name.

The grid module 82 receives the data segments and may manipulate (e.g.,compression, encryption, cyclic redundancy check (CRC), etc.) each ofthe data segments before performing an error coding function of theerror coding dispersal storage function to produce a pre-manipulateddata segment. After manipulating a data segment, if applicable, the gridmodule 82 error encodes (e.g., Reed-Solomon, Convolution encoding,Trellis encoding, etc.) the data segment or manipulated data segmentinto X error coded data slices 42-44.

The value X, or the number of pillars (e.g., X=16), is chosen as aparameter of the error coding dispersal storage function. Otherparameters of the error coding dispersal function include a readthreshold T, a write threshold W, etc. The read threshold (e.g., T=10,when X=16) corresponds to the minimum number of error-free error codeddata slices required to reconstruct the data segment. In other words,the DS processing module 34 can compensate for X−T (e.g., 16−10=6)missing error coded data slices per data segment. The write threshold Wcorresponds to a minimum number of DS storage units that acknowledgeproper storage of their respective data slices before the DS processingmodule indicates proper storage of the encoded data segment. Note thatthe write threshold is greater than or equal to the read threshold for agiven number of pillars (X).

For each data slice of a data segment, the grid module 82 generates aunique slice name 37 and attaches it thereto. The slice name 37 includesa universal routing information field and a vault specific field and maybe 48 bytes (e.g., 24 bytes for each of the universal routinginformation field and the vault specific field). As illustrated, theuniversal routing information field includes a slice index, a vault ID,a vault generation, and a reserved field. The slice index is based onthe pillar number and the vault ID and, as such, is unique for eachpillar (e.g., slices of the same pillar for the same vault for anysegment will share the same slice index). The vault specific fieldincludes a data name, which includes a file ID and a segment number(e.g., a sequential numbering of data segments 1-Y of a simple dataobject or a data block number).

Prior to outputting the error coded data slices of a data segment, thegrid module may perform post-slice manipulation on the slices. Ifenabled, the manipulation includes slice level compression, encryption,CRC, addressing, tagging, and/or other manipulation to improve theeffectiveness of the computing system.

When the error coded data slices of a data segment are ready to beoutputted, the grid module 82 determines which of the DS storage units36 will store the EC data slices based on a dispersed storage memorymapping associated with the user's vault and/or DS storage unitattributes. The DS storage unit attributes may include availability,self-selection, performance history, link speed, link latency,ownership, available DSN memory, domain, cost, a prioritization scheme,a centralized selection message from another source, a lookup table,data ownership, and/or any other factor to optimize the operation of thecomputing system. Note that the number of DS storage units 36 is equalto or greater than the number of pillars (e.g., X) so that no more thanone error coded data slice of the same data segment is stored on thesame DS storage unit 36. Further note that EC data slices of the samepillar number but of different segments (e.g., EC data slice 1 of datasegment 1 and EC data slice 1 of data segment 2) may be stored on thesame or different DS storage units 36.

The storage module 84 performs an integrity check on the outboundencoded data slices and, when successful, identifies a plurality of DSstorage units based on information provided by the grid module 82. Thestorage module 84 then outputs the encoded data slices 1 through X ofeach segment 1 through Y to the DS storage units 36. Each of the DSstorage units 36 stores its EC data slice(s) and maintains a localvirtual DSN address to physical location table to convert the virtualDSN address of the EC data slice(s) into physical storage addresses.

In an example of a read operation, the user device 12 and/or 14 sends aread request to the DS processing unit 14, which authenticates therequest. When the request is authentic, the DS processing unit 14 sendsa read message to each of the DS storage units 36 storing slices of thedata object being read. The slices are received via the DSnet interface32 and processed by the storage module 84, which performs a parity checkand provides the slices to the grid module 82 when the parity check wassuccessful. The grid module 82 decodes the slices in accordance with theerror coding dispersal storage function to reconstruct the data segment.The access module 80 reconstructs the data object from the data segmentsand the gateway module 78 formats the data object for transmission tothe user device.

FIG. 4 is a schematic block diagram of an embodiment of a grid module 82that includes a control unit 73, a pre-slice manipulator 75, an encoder77, a slicer 79, a post-slice manipulator 81, a pre-slice de-manipulator83, a decoder 85, a de-slicer 87, and/or a post-slice de-manipulator 89.Note that the control unit 73 may be partially or completely external tothe grid module 82. For example, the control unit 73 may be part of thecomputing core at a remote location, part of a user device, part of theDS managing unit 18, or distributed amongst one or more DS storageunits.

In an example of write operation, the pre-slice manipulator 75 receivesa data segment 90-92 and a write instruction from an authorized userdevice. The pre-slice manipulator 75 determines if pre-manipulation ofthe data segment 90-92 is required and, if so, what type. The pre-slicemanipulator 75 may make the determination independently or based oninstructions from the control unit 73, where the determination is basedon a computing system-wide predetermination, a table lookup, vaultparameters associated with the user identification, the type of data,security requirements, available DSN memory, performance requirements,and/or other metadata.

Once a positive determination is made, the pre-slice manipulator 75manipulates the data segment 90-92 in accordance with the type ofmanipulation. For example, the type of manipulation may be compression(e.g., Lempel-Ziv-Welch, Huffman, Golomb, fractal, wavelet, etc.),signatures (e.g., Digital Signature Algorithm (DSA), Elliptic Curve DSA,Secure Hash Algorithm, etc.), watermarking, tagging, encryption (e.g.,Data Encryption Standard, Advanced Encryption Standard, etc.), addingmetadata (e.g., time/date stamping, user information, file type, etc.),cyclic redundancy check (e.g., CRC32), and/or other data manipulationsto produce the pre-manipulated data segment.

The encoder 77 encodes the pre-manipulated data segment 92 using aforward error correction (FEC) encoder (and/or other type of erasurecoding and/or error coding) to produce an encoded data segment 94. Theencoder 77 determines which forward error correction algorithm to usebased on a predetermination associated with the user's vault, a timebased algorithm, user direction, DS managing unit direction, controlunit direction, as a function of the data type, as a function of thedata segment 92 metadata, and/or any other factor to determine algorithmtype. The forward error correction algorithm may be Golay,Multidimensional parity, Reed-Solomon, Hamming, Bose Ray ChauduriHocquenghem (BCH), Cauchy-Reed-Solomon, or any other FEC encoder. Notethat the encoder 77 may use a different encoding algorithm for each datasegment 92, the same encoding algorithm for the data segments 92 of adata object, or a combination thereof.

The encoded data segment 94 is of greater size than the data segment 92by the overhead rate of the encoding algorithm by a factor of X/T, whereX is the width or number of slices, and T is the read threshold. In thisregard, the corresponding decoding process can accommodate at most X−Tmissing EC data slices and still recreate the data segment 92. Forexample, if X=16 and T=10, then the data segment 92 will be recoverableas long as 10 or more EC data slices per segment are not corrupted.

The slicer 79 transforms the encoded data segment 94 into EC data slicesin accordance with the slicing parameter from the vault for this userand/or data segment 92. For example, if the slicing parameter is X=16,then the slicer 79 slices each encoded data segment 94 into 16 encodedslices.

The post-slice manipulator 81 performs, if enabled, post-manipulation onthe encoded slices to produce the EC data slices. If enabled, thepost-slice manipulator 81 determines the type of post-manipulation,which may be based on a computing system-wide predetermination,parameters in the vault for this user, a table lookup, the useridentification, the type of data, security requirements, available DSNmemory, performance requirements, control unit directed, and/or othermetadata. Note that the type of post-slice manipulation may includeslice level compression, signatures, encryption, CRC, addressing,watermarking, tagging, adding metadata, and/or other manipulation toimprove the effectiveness of the computing system.

In an example of a read operation, the post-slice de-manipulator 89receives at least a read threshold number of EC data slices and performsthe inverse function of the post-slice manipulator 81 to produce aplurality of encoded slices. The de-slicer 87 de-slices the encodedslices to produce an encoded data segment 94. The decoder 85 performsthe inverse function of the encoder 77 to recapture the data segment90-92. The pre-slice de-manipulator 83 performs the inverse function ofthe pre-slice manipulator 75 to recapture the data segment 90-92.

FIG. 5 is a diagram of an example of slicing an encoded data segment 94by the slicer 79. In this example, the encoded data segment 94 includesthirty-two bits, but may include more or less bits. The slicer 79disperses the bits of the encoded data segment 94 across the EC dataslices in a pattern as shown. As such, each EC data slice does notinclude consecutive bits of the data segment 94 reducing the impact ofconsecutive bit failures on data recovery. For example, if EC data slice2 (which includes bits 1, 5, 9, 13, 17, 25, and 29) is unavailable(e.g., lost, inaccessible, or corrupted), the data segment can bereconstructed from the other EC data slices (e.g., 1, 3 and 4 for a readthreshold of 3 and a width of 4).

FIG. 6 is a schematic block diagram of another embodiment of a computingsystem that includes at least one user device 102, a plurality (two ormore) of dispersed storage (DS) processing units 1-2, and a dispersedstorage network (DSN) memory 22. The DSN memory 22 includes a pluralityof dispersed storage (DS) units 36. Each of the DS processing unitsincludes one or more processing modules, may be a separate device, maybe contained in one or more common devices, and/or may be containedwithin a user device. Note that the system may further include aplurality of user devices 102 and/or a plurality of DSN memories 22.

Each DS processing unit 1-2 has a unique Internet protocol (IP) addressto facilitate individual addressing by the user device(s), the DS units36, and/or other system elements (not shown). For example, DS processingunit 1 has IP address 192.168.1.34 and DS processing unit 2 has IPaddress 192.168.1.35. In addition, the DS processing units 1-2 maintaina responsibility indicator with respect to responding to DSN memoryaccess requests from the user device 102. The responsibility indicatormay indicate various responsibility levels including no responsibility,a proxy DS processing module, and/or a master DS processing module. Forexample, DS processing unit 1 has the responsibility of the master DSprocessing module and DS processing unit 2 has the responsibility of theproxy DS processing module during a first time period. In this example,DS processing unit 1 directly processes DSN memory 22 access requestsfrom the user device 102 during the first time period and DS processingunit 2 indirectly processes DSN memory 22 access requests from the userdevice 102 during the first time period by forwarding them to DSprocessing unit 1.

The master DS processing module responsibility includes at least fouractivities. The first includes a determination of the master DSprocessing unit. The second includes establishing a connection betweenthe DSN memory 22 and the master DS processing unit. The third includesestablishing a connection between the user device 102 and the master DSprocessing unit. The fourth includes facilitating the utilization of theDSN memory 22 by the user device 102.

In the first activity, the DS processing units 1-2 negotiate todetermine which one of them will serve as the active master for the userdevice 102. The determination may be based on one or more of a randomdecision, a schedule, a predetermination, a command, a time durationsince the last determination, DS processing unit performance, DSprocessing unit errors, DS processing unit capabilities, and a computingsystem loading level indicator. In an example, the DS processing unit 1with the master DS processing unit responsibility processes all of theDSN memory 22 access requests from the user device 102. In an example,DS processing unit 2 with the proxy responsibility assists the master DSprocessing unit 1 by transferring messages between the master DSprocessing unit 1 and the user device 102. An embodiment of method fordetermining the master DS processing unit will be discussed in greaterdetail with reference to FIG. 8.

In the second activity, the master DS processing unit 1-2 establishes aconnection with the DS units 36 of the DSN memory 22. In an example, theDS unit 36 queries one or more of the DS processing units 1-2 todetermine which one is the active master. Once the master is identified,the DS units 36 establish an authenticated connection with the master DSprocessing unit by exchanging signed certificates with a public keyinfrastructure (PKI) scheme.

In the third activity, the master DS processing unit establishes aconnection with the user device 102. In an example, the user device 102queries one or more of the DS processing units to determine itsresponsibilities. Having identified the master, the user deviceestablishes an authenticated connection with the master DS processingunit 1 by exchanging signed certificates with a public keyinfrastructure (PKI) scheme. In addition, or in the alternative, theuser device 102 establishes an authenticated connection with DSprocessing unit 2 that is not the master by exchanging signedcertificates with a public key infrastructure (PKI) scheme. In thismanner, the user device 102 may choose to use the proxy (e.g.,non-master) DS processing unit when the master DS processing unit is notreadily available (e.g., when the network 24 is down to the masterand/or when the master is too busy).

In the fourth activity, the master DS processing unit facilitates theuser device 102 accessing the DSN memory 22. For example, the master DSprocessing unit receives a DSN memory access request (e.g., store,retrieve, delete, list) from the user device over the establishedconnection and processes it accordingly. Alternatively, the proxy DSprocessing unit receives the DSN memory access request from the userdevice and forwards the DSN memory access request to the master DSprocessing unit 1 for processing. In an instance, the user device 102sends the DSN memory access request to DS processing unit 2 that is notthe master. As another alternative, the proxy DS processing unitreceives the DSN memory access request from the user device, processesit, and may further information the master DS processing unit of the DSNmemory access request and processing of it.

FIG. 7 is a flowchart illustrating an example of accessing a dispersedstorage network (DSN) memory. The method begins at step 104 where aprocessing module of a user device (or other device of the system)determines to access the DSN memory. Such a determination may be basedon a requirement to perform one or more of storing data, retrievingdata, deleting data, and listing data. At step 106, the processingmodule selects one of the dispersed storage (DS) processing modules tobe a master for facilitating access to the DSN memory. Such a selectionmay be based on one or more of a query, a slice name associated with theencoded data slice, a vault identifier, a DSN memory identifier, a listof DS processing module identifiers, a DS processing module assignmentlist, a DS processing module performance indicator, a DS processingmodule capability indicator, and a last utilized DS processing moduleidentifier. In an example, the processing module determines a random DSprocessing module of a plurality of candidate master DS processingmodules. In another example, the processing module determines a DSprocessing module of a plurality of master DS processing units where theDS processing module was not recently utilized (e.g., round robinselection).

The method continues at step 108 where the processing module sends a DSNmemory access request to the selected DS processing module (e.g., masteror proxy). Note that the access request includes one of more of arequest to store an encoded data slice, a request to delete the encodeddata slice, a request to list the encoded data slice, and a request toretrieve the encoded data slice. The selected DS processing moduledetermines if it will processes the request, creates a request response,and sends the request response to the processing module of the userdevice. The request response indicates that the selected DS processingmodule will process the request or not. The method of determination ofthe response is discussed in greater detail with reference to FIG. 9.

At step 112, the processing module receives the request response fromthe selected DS processing module and determines if the response isfavorable. Note that the response includes one of an active masteraccess indicator, a master DS processing module identifier, a proxyaccess indicator, and a rejection message. The processing moduledetermines that the response is favorable when the response indicatesthat the selected DS processing module will process the request (e.g.,directly as the master or as a proxy to a master) and determines thatthe response is not favorable when no response is received within agiven time frame or when the response to the access request does notinclude an access indication.

At step 114, the processing module saves a DS processing moduleidentifier of the selected DS processing module with the unfavorableresponse and the method branches back to step 106 where the processingmodule selects another DS processing module. Alternatively, or inaddition to, the processing module receives the identity of the other DSprocessing module in the response. When the response is favorable, themethod continues at step 116 where the processing module and selected DSprocessing module complete a transaction of the DSN memory accessrequest (e.g., the processing module sends a data object to the DSprocessing module for storage in the DSN memory when the access requestincludes a storage request).

FIG. 8 is a flowchart illustrating an example of determining a masterdispersed storage (DS) processing module. The method begins at step 118where a processing module attempts to discover companion DS processingmodules, which may be a group of DS processing modules where at leastone DS processing modules is a master DS processing module. For example,one DS processing module is a master at a time and masterresponsibilities may change from time to time. As another example, twoor more DS processing modules are co-masters and their respective masterresponsibilities may change from time to time.

The discovery of the companion DS processing modules may be based on oneor more of a list, a command, a latency ping test, a configuration file,and a query. For example, the processing module discovers a companion DSprocessing module via a latency ping test (e.g., where the configurationfile specifies selection based on low latencies of the same site).

The method continues at step 120 where the processing module negotiatesthe master responsibility with the other companion DS processingmodule(s) based on one or more of a random choice, a schedule, apredetermination, a command, a time duration since the lastdetermination, DS processing module performance, DS processing moduleerrors, DS processing module capabilities, and a computing systemloading level indicator. For example, one processing module maynegotiate that one or more of the master responsibilities to another DSprocessing module when it has not recently served as the masterprocessing module.

At step 122, the processing module confirms the master DS processingmodule responsibility with the other companion DS processing module(s)by sending a confirmation message to the other companion DS processingmodule(s). Each of the DS processing modules then saves their currentmaster responsibilities (if any) and those of the other DS processingmodules.

FIG. 9 is a flowchart illustrating an example of processing a dispersedstorage network (DSN) memory access request. The method begins at step124 where a processing module of a DS processing unit receives, from auser device, an access request (e.g., store, retrieve, delete, list) toa dispersed storage network (DSN) memory. At step 126, the processingmodule determines responsibility for the access request (e.g., does ithave master responsibilities). Such a determination includes at leastone of obtaining a master DS processing module indicator, obtaining aproxy access indicator, sending a query message, interpreting a slicename associated with the encoded data slice, interpreting a user deviceidentifier, interpreting a vault identifier, interpreting a DSN memoryidentifier, interpreting a list of dispersed storage (DS) processingmodule identifiers, interpreting a DS processing module assignment list,interpreting a DS processing module performance indicator, interpretinga DS processing module capability indicator.

When the processing module is the master DS processing module, themethod continues at step 128 where processing module processes therequest from the user device. Note that processing the request mayinclude sending an access request response to the user device to confirmprocessing, accessing the DSN memory over the connections with the DSunits to store, retrieve, and/or delete data, and to send and receivedata to and from the user device.

When the processing module is not the master DS processing module, themethod continues at step 130 where the processing module determines ifit has proxy responsibilities. If not, the method continues to step 132where the processing module ignores the access request or sends arejection message (e.g., indicating that the processing module is not amaster and not a proxy). Alternatively, or in addition to, theprocessing module may send a message to the user device that identifiesthe master DS processing module when the responsibility is a redirectionfunction.

When the processing module has proxy responsibilities, the methodcontinues at step 134 where the processing module identifies a master DSprocessing module. The master DS processing module may be identified byobtaining a master DS processing module indicator, sending a querymessage, interpreting a slice name associated with the encoded dataslice, interpreting a vault identifier, interpreting a DSN memoryidentifier, interpreting a list of DS processing module identifiers,accessing a DS processing module assignment list, interpreting a DSprocessing module performance indicator, interpreting a DS processingmodule capability indicator, and/or interpreting a last utilized DSprocessing module identifier. For example, the processing moduleidentifies the master DS processing module based on accessing the DSprocessing module assignment list.

At step 136, the processing module performs a proxy function related tothe access request on behalf of the user device with the master DSprocessing module. The proxy function includes one or more of forwardingthe access request to the master DS processing module, receiving aresponse from the master DS processing module, and forwarding theresponse to the user device.

FIG. 10 is a flowchart illustrating an example of establishing aconnection with a dispersed storage (DS) unit. The method begins at step138 where a processing module receives a request (e.g., store, retrieve,delete, list) to access a DSN memory from a user device. The request mayinclude one or more of the user ID, a request type, authenticationcredentials (e.g., a public key interface (PKI) signed certificate), asecurity indicator, a performance indicator, and a priority indicator.

At step 140, the processing module determines a DS unit storage set thatincludes the DS units that make up pillars of where slices are storedfor the same data segment. Such a determination may be based on one ormore of a lookup of the virtual DSN address to physical location table,a predetermination, a command, a list, the user ID, the request type,the authentication credentials (e.g., a PKI signed certificate), thesecurity indicator, the performance indicator, and the priorityindicator.

At step 142, the processing module determines whether a connectionalready exists with each DS unit of the DS unit storage set based on oneor more of a lookup of previous connections, a predetermination, acommand, a list, the user ID, the request type, and a query. Note that aconnection indicates the DS processing unit and the DS unit havepreviously successfully exchanged authentication credentials. In anexample, the exchange may include establishing cipher algorithms andkeys.

When the connection does not exist, the method continues at step 144where the processing module establishes a new connection with each DSunit that does have a connection by sending the user ID and theauthentication credentials to the DS unit(s). The processing module addsthe connection in a list, which is referenced during subsequent DSNmemory access requests. At step 146, the processing module processes therequest from the user device. Note that processing the request mayinclude sending an access request response to the user device to confirmprocessing, accessing the DSN memory over the connections with the DSunits to store, retrieve, and/or delete data, and to send and receivedata to and from the user device.

When the connection exists, the method continues at step 148 where theprocessing module determines whether to utilize the existing connection.Such a determination may be based on one or more of a lookup of previousconnections, a measured connection utilization indicator, a connectioncapacity estimate, a connection load estimate for the user device, apredetermination, a command, a list, the user ID, the request type, thesecurity indicator, the performance indicator, the priority indicator,and a query. For example, the DS processing may determine to utilize anexisting connection when the difference between the connection capacityestimate and the sum of the connection load estimate for the user deviceand the measured connection utilization indicator is greater than athreshold. For instance, there is more than a threshold of estimatedcapacity left over after adding the estimated user device transactiontraffic to the existing connection load. Note that there may be morethan one connection between the DS processing unit and the DS unit.Further note that each connection may be utilized for one or more userdevice in user-device-to-DSN-memory access transactions. For example,the processing module may determine to trunk user transactions over apool of connections.

When an existing connection is going to be used, the method continues atstep 150 where the DS processing module determines which existingconnection to utilize and utilizes the existing connection by sendingthe user ID and the authentication credentials to the DS unit(s) toauthenticate the user (e.g., but not to establish a new connection).Such a determination may based on one or more of a lookup of previousconnections, a connection capacity estimate, a connection load estimatefor the user device, a predetermination, a command, a list, the user ID,the request type, the security indicator, the performance indicator, thepriority indicator, and/or a query. In addition, the processing moduleadds or updates the connection in the connection list. At step 152, theprocessing module processes the request from the user device, which mayinclude sending an access request response to the user device to confirmprocessing, accessing the DSN memory over the connections with the DSunits to store, retrieve, and/or delete data, and to send and receivedata to and from the user device.

When an existing connection is not going to be used, the methodcontinues at step 154 where the processing module adds anotherconnection, notifies the user device, updates credentials. For example,the processing module determines to add a connection when the differencebetween the connection capacity estimate and the sum of the connectionload estimate for the user device and the measured connectionutilization indicator is less than a threshold. For instance, there isless than a threshold (e.g., not enough) of estimated capacity left overafter adding the estimated user device transaction traffic to theexisting connection load. In another example, the processing moduledetermines to add a connection when a security indicator warrants a newconnection (e.g., a higher than average level of security is required).In addition, the processing module adds the connection to the connectionlist. At step 156, the processing module processes the request from theuser device as previously discussed.

FIG. 11 is a flowchart illustrating an example of establishing a secureconnection. The method begins at step 158 where a processing module(e.g., of a DS processing unit) receives a request (e.g., store,retrieve, delete, list) to access the DSN memory from a user device. Therequest may include one or more of a user ID, a request type, data type,user device authentication credentials (e.g., a PKI signed certificate),a security indicator, a performance indicator, and/or a priorityindicator.

At step 160, the processing module determines security requirements forthe connection, where the security requirements may specify a level ofprotection from tampering and/or ease dropping. Such a determination maybe based on one or more of a user vault lookup, the user ID, the requesttype, the data type, the user device authentication credentials (e.g., aPKI signed certificate), the security indicator, the performanceindicator, and/or the priority indicator. For example, the processingmodule determines security requirements with no tampering or easedropping protection when the data type indicates a public text documentand the security indictor indicates no security is required. In anotherexample, the processing module determines security requirements withtampering protection and little ease dropping protection when the datatype indicates a private financial document and the security indictorindicates little security is required. In another example, theprocessing module determines security requirements with tamperingprotection and ease dropping protection when the data type indicates aconfidential document and the security indictor indicates highersecurity is required.

At step 162, the processing module determines a DS unit storage set,which includes DS units that make up pillars of where slices are storedfor the same data segment. Such a determination may be based on one ormore of a lookup of the virtual DSN address to physical location table,a user vault lookup, the security requirements, security capabilities ofthe DS unit (e.g., cipher algorithms), security attack history of the DSunit, a predetermination, a command, a list, the user ID, the requesttype, the security indicator, the performance indicator, and thepriority indicator.

At step 164, the processing module determines DS unit connectionsecurity approach that includes a first level with no tamperingprotection and no ease dropping protection, a second level withtampering protection and no ease dropping protection, or a third levelwith tampering protection and ease dropping protection. For example, thefirst level with no tampering protection and no ease dropping protectionmay be implemented with transmission control protocol (TCP). The secondlevel with tampering protection and no ease dropping protection may beimplemented with transport layer security (TLS) with a null cipher. Thethird level with tampering protection and ease dropping protection maybe implemented with transport layer security (TLS) with a cipher.

The processing module determination of the DS unit connection securityapproach may be based on one or more of the security requirements, auser vault lookup, security capabilities of the DS unit (e.g., cipheralgorithms, location), security attack history of the DS unit, apredetermination, a command, a list, the user ID, the request type, thesecurity indicator, the performance indicator, and/or the priorityindicator. In an example, the processing module determines a differentsecurity approach for two or more DS units of the same DS unit storageset. For instance, a data segment may have a portion of its slicesstored in one part of the DSN memory with one security approach and mayhave another portion of its slices stored in another part of the DSNmemory with another security approach. As a more specific example, in apillar width n=16 system, the processing module determines that the DSunits of pillars 1-4 utilize the TCP approach (e.g., since they havesuperior security capabilities being located in the same rack as the DSprocessing unit), that the DS units of pillars 5-12 utilize the TLS nullcipher approach (e.g., since they have good security capabilities beinglocated in the same building complex as the DS processing unit), andthat the DS units of pillars 13-16 utilize the TLS with a cipherapproach (e.g., since they have the lowest security capabilities beinglocated in different cities from the DS processing unit). In anotherexample, the processing module determines that the same securityapproach shall be used for the DS units of the same DS unit storage set.

At step 168, the processing module establishes a TCP connection bysending the user ID and the authentication credentials to the DS unitwhen the security approach for the DS unit connection is to be TCP. Inaddition, the processing module adds the connection and its securityapproach to the connections list. At step 170, the processing moduleprocesses the request from the user device, which may include sending anaccess request response to the user device to confirm processing,accessing the DSN memory over the TCP connection with the DS unit tostore, retrieve, and/or delete data, and to send and receive data to andfrom the user device.

At step 172, the processing module establishes a TLS null cipherconnection by sending the user ID, the authentication credentials, and akey to utilize in the hash based message authentication code (HMAC)integrity verification to the DS unit when the DS processing determinesthe connection security approach for the DS unit connection to be TLSnull cipher. In addition, the processing module adds the connection andits security approach to the connection list. At step 174, theprocessing module processes the request from the user device, which mayinclude sending an access request response to the user device to confirmprocessing, accessing the DSN memory over the TLS null cipher connectionwith the DS unit to store, retrieve, and/or delete data, and to send andreceive data to and from the user device. Note that the messages areverified for integrity by checking the HMAC of the payload utilizing thekey.

At step 176, the processing module establishes a TLS with a cipherconnection by sending the user ID, the authentication credentials, a keyto utilize in the HMAC integrity verification, a cipher algorithmchoice, and a cipher key to encrypt message payload to the DS unit whenthe DS processing determines the connection security approach for the DSunit connection to be TLS with a cipher. The processing module maydetermine the cipher algorithm choice based on the strongest cipher thatthe DS processing unit and DS unit both support (e.g., from a cipherlist or cipher query). In addition, the processing module adds theconnection and its security approach to the connection list. At step178, the processing module processes the request from the user device,which may include sending an access request response to the user deviceto confirm processing, accessing the DSN memory over the TLS null cipherconnection with the DS unit to store, retrieve, and/or delete data, andto send and receive data to and from the user device. Note that themessages are verified for integrity by checking the HMAC of the payloadutilizing the key. Further note that the payload is encrypted on one endof the connection and decrypted on the other end of the connection byutilizing the cipher algorithm and the cipher key.

At step 180, processing module establishes other connection types bysending the user ID and the authentication credentials to the DS unitwhen the DS processing determines the connection security approach forthe DS unit connection to be other. At step 182, the processing moduleprocesses the request from the user device as previously discussed.

FIG. 12 is a flowchart illustrating an example of detecting a filechange. The method begins at step 184 where a processing module of auser device calculates a hash of a data object being checked for achange since a previous backup. At step 186, the processing moduleretrieves the last hash saved for the data object based on accessing alist utilizing a data object name. The list links the hash of the dataobject and the data object name when it is sent to a DS processing unitfor backup in the DSN memory.

The method continues at step 188 where the processing module determinesif the calculated hash is the same as the last hash saved for the dataobject by comparing the two. Alternatively, the processing moduledetermines if the file has changed by comparing the file to a saved lastfile (e.g., locally or in the DSN memory). When they are the same, themethod continues at step 190 where the processing module tests anotherdata object and the method repeats at step 184.

When the hashes are not the same, the method continues at step 192 wherethe processing module sends the data object, the data object name, and abackup command to a DS processing unit. In an example, the processingmodule sends the entire data object. In another example, the processingmodule sends a portion of the data object that has changed (e.g.,determined by a more granular hash test) and a position of changeindicator (e.g., which byte number range of a change insert). At step194, the processing module saves the hash of the data object. Note thatthe method may repeat such that the processing module examines more dataobjects to detect changes.

Alternatively, or in addition to, the processing module may determine todelete an older data object revision (e.g., based on age, a schedule, alack of use, a policy, a command, etc.) and may send a delete revisioncommand with the revision number and data object name to the DSprocessing unit. The DS processing of the DS processing unit may deleteEC data slices from the DSN memory for data segments that are unique andnot in common with data segments of other revisions of the same dataobject.

FIG. 13 is a flowchart illustrating an example of backing up a dataobject. The method begins at step 196 where a processing module (e.g.,of a DS processing unit) receives the data object, a data object name,and a backup command from a user device. At step 198, the processingmodule determines operational parameters based on one or more of alookup of the virtual DSN address to physical location table, a command,a list, a vault lookup, and a predetermination. At step 200, theprocessing module creates a data segment of the data object inaccordance with the operational parameters. Note that the process beginswith the first data segment and may later loop back for subsequent datasegments.

The method continues at step 202 where the processing module retrievesencoded data slices of the data segment and recreates a data segmentfrom the retrieved slices in accordance with the operational parameters.At step 204, the DS processing determines if the recreated data segmentand the data segment are substantially the same. When the data segmentsare not substantially the same, the method continues at step 206 wherethe processing module determines if the data segment number is the lastdata segment of the data object based on the data segment sizes and/orthe size of the data object. When it is, the method is completed. Whenit is not the last data segment, the method continues at step 208 wherethe processing module targets the next data segment and the methodrepeats at step 200.

When the data segments are substantially the same, the method continuesat step 212 where the processing module creates slices of the datasegment in accordance with the operational parameters and sends theslices to the DSN memory with a store command for storage therein. In anexample, the processing module determines to utilize the sameoperational parameters for the same data segment numbers of differentrevisions. In another example, the processing module determines toutilize different operational parameters for the same data segmentnumbers of different revisions. For instance, the data segment size maybe different in the new revision. In another example, the processingmodule determines to utilize a less reliable distributed data approachfor the new revision data segment since inherent backups of the olderrevision data segment are already stored in the DSN memory.

In addition, the processing module updates the user vault with a newrevision number and any operational parameter changes for all updateddata segments (e.g., by data segment number) of the same received dataobject. Alternatively, the data object retrieval method may utilize theuser vault information including which data segments have new data andhow they were stored. For instance, a recreated data object may bedetermined from a collection of recreated data segments of the latestrevision (e.g., which may include older revision numbers and newerrevision numbers).

FIG. 14 is a flowchart illustrating an example of cataloging ofdispersed storage network (DSN) memory content. The method begins withstep 214 where a processing module (e.g., of one of the DS processingunit, the storage integrity processing unit, the DS unit, the userdevice, the DS managing unit, and/or a cataloging server) determines adata object name of a data object to catalog. Such a determination maybe based on one or more of a last cataloged data object, a new dataobject received for storage in the DSN memory, a command, a list, adirectory, a user vault lookup, and/or a predetermination. For example,the processing module determines to move to the next data object into auser directory. At step 216, the processing module determines slicenames and operational parameters of the data object based on the dataobject name and the user vault as previously discussed.

The method continues at step 218 where the processing module retrievesslices from the DSN memory for one or more data segments where the datasegments may be targeted to provide the rich information. For example,the processing module targets the first data segments where informationrich headers and descriptors may be located. In another example, theprocessing module targets the last data segments where information richsummaries and links may be located. At step 220, the processing modulerecreates the one or more data segments based on the retrieved slices inaccordance with the operational parameters.

The method continues at step 222 where the processing module determinesand saves metadata of the data segment in the user vault and/or a listlinked to the data object name. Such a determination of the metadata maybe based on searching and finding information related to one or more oftype of data, key words, phrases, lyrics, patterns, people references,places, things, relationships to other objects, a priority indicator, asecurity indicator, a user ID, and a timestamp. In an example, themetadata determination is biased by the data type and filename (e.g.,video file, text file, sound file). For example, the processing modulesearches for a name of a person when the data type indicates a textfile. In another example, the processing module searches for a patternof a face when the data type indicates a picture file.

At step 224, the processing module determines whether more metadata isrequired for this data object based on comparing the amount of metadatasaved so far to a completeness threshold. In an example, thecompleteness threshold may require a minimum number of entries in a listof categories based on the data type or other clarifier. The processingmodule may determine that no more metadata is required when the amountof metadata saved so far is greater than the completeness threshold ineach required category. The method ends with step 228 when theprocessing determines that no more metadata is required.

When more metadata is required, the method continues at step 226 wherethe processing module determines another data segment of the data objectto examine. Such a determination may be based on one or more of howclose the amount of metadata saved so far is to the completenessthreshold, how many data segments are left, what portion of datasegments have been examined, and the categories that have not reachedtheir completeness thresholds. The method branches back to step 218.

FIG. 15 is a flowchart illustrating an example of searching dispersedstorage network (DSN) memory. The method begins at step 230 where aprocessing module (e.g., of one of the DS processing unit, the storageintegrity processing unit, the DS unit, the user device, the DS managingunit, and/or a cataloging server) receives search parameters from arequester (e.g., a user device). At step 232, the processing moduledetermines desired data in DSN memory by comparing the search parametersfor similarities to DSN memory metadata. In an example, the metadata waspreviously stored in a list or user vault. In another example, themetadata is obtained based on the search parameters. In yet anotherexample, the metadata is obtained by a combination of previously storedmetadata in a list or user vault and metadata based on the searchparameters. The metadata is linked to one or more data objects stored asencoded and sliced data segments.

The method continues at step 234 where the processing module determinesa data object name of the data object based on a linked list of metadatato data object names for metadata that is similar to the searchparameters and which data objects may have been examined further so far(as discussed below). At step 236, the processing module determinesslice names and operational parameters associated with the data objectbased on the data object name and the user vault as previouslydiscussed. At step 238, the processing module retrieves slices from theDSN memory for one or more data segments based on a lookup of DSNlocations in a virtual DSN address to physical location table. Theretrieved slices may target data segments such as information headers atthe beginning of the data object as discussed previously. At step 240,the processing module decodes the retrieved slices in accordance withthe operational parameters to re-create one or more data segments.

The method continues at step 242 where the processing module determinesmetadata of the recreated data segment(s) as previously discussed. Atstep 244, the processing module determines whether the recreated datasegment(s) compares favorably to the search parameters by comparing thetwo, which, for example, occurs when the two substantially include thesame or similar information.

When the comparison is not favorable, the method branches to step 246where the processing module determines whether the search has beenexhausted of this data object based on completion of examiningsubstantially all of the data segments. When exhausted, the methodrepeats at step. When not exhausted, the method continues at step 250where the processing module determines another data segment to examinefor this data object. The processing module may selection another datasegment based on which data segments have been examined so far and whichcategories are rich with information (e.g., places, patterns, names, keywords, etc.). The method then repeats at step 238.

When the comparison of step 244 is favorable, the method continues atstep 252 where the processing module retrieves slices for the remainingun-retrieved data segments. At step 254, the processing module recreatesthe data object based on the previously recreated data segments and theretrieved slices for the remaining un-retrieved data segments. At step256, the processing module sends the data object that matched the searchparameters to the requester.

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “operably coupled to”, “coupled to”, and/or “coupling” includesdirect coupling between items and/or indirect coupling between items viaan intervening item (e.g., an item includes, but is not limited to, acomponent, an element, a circuit, and/or a module) where, for indirectcoupling, the intervening item does not modify the information of asignal but may adjust its current level, voltage level, and/or powerlevel. As may further be used herein, inferred coupling (i.e., where oneelement is coupled to another element by inference) includes direct andindirect coupling between two items in the same manner as “coupled to”.As may even further be used herein, the term “operable to” or “operablycoupled to” indicates that an item includes one or more of powerconnections, input(s), output(s), etc., to perform, when activated, oneor more its corresponding functions and may further include inferredcoupling to one or more other items. As may still further be usedherein, the term “associated with”, includes direct and/or indirectcoupling of separate items and/or one item being embedded within anotheritem. As may be used herein, the term “compares favorably”, indicatesthat a comparison between two or more items, signals, etc., provides adesired relationship. For example, when the desired relationship is thatsignal 1 has a greater magnitude than signal 2, a favorable comparisonmay be achieved when the magnitude of signal 1 is greater than that ofsignal 2 or when the magnitude of signal 2 is less than that of signal1.

While the transistors in the above described figure(s) is/are shown asfield effect transistors (FETs), as one of ordinary skill in the artwill appreciate, the transistors may be implemented using any type oftransistor structure including, but not limited to, bipolar, metal oxidesemiconductor field effect transistors (MOSFET), N-well transistors,P-well transistors, enhancement mode, depletion mode, and zero voltagethreshold (VT) transistors.

The present invention has also been described above with the aid ofmethod steps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention.

The present invention has been described, at least in part, in terms ofone or more embodiments. An embodiment of the present invention is usedherein to illustrate the present invention, an aspect thereof, a featurethereof, a concept thereof, and/or an example thereof. A physicalembodiment of an apparatus, an article of manufacture, a machine, and/orof a process that embodies the present invention may include one or moreof the aspects, features, concepts, examples, etc. described withreference to one or more of the embodiments discussed herein.

The present invention has been described above with the aid offunctional building blocks illustrating the performance of certainsignificant functions. The boundaries of these functional buildingblocks have been arbitrarily defined for convenience of description.Alternate boundaries could be defined as long as the certain significantfunctions are appropriately performed. Similarly, flow diagram blocksmay also have been arbitrarily defined herein to illustrate certainsignificant functionality. To the extent used, the flow diagram blockboundaries and sequence could have been defined otherwise and stillperform the certain significant functionality. Such alternatedefinitions of both functional building blocks and flow diagram blocksand sequences are thus within the scope and spirit of the claimedinvention. One of average skill in the art will also recognize that thefunctional building blocks, and other illustrative blocks, modules andcomponents herein, can be implemented as illustrated or by discretecomponents, application specific integrated circuits, processorsexecuting appropriate software and the like or any combination thereof.

1. A method comprises: selecting one of a plurality of dispersed storage(DS) processing modules for facilitating access to a dispersed storagenetwork (DSN) memory; sending a DSN memory access request to the one ofthe plurality of DS processing modules; when no response is receivedwithin a given time frame or when the response to the access requestdoes not include an access indication, selecting another one of theplurality of DS processing modules; and sending the DSN memory accessrequest to the another one of the plurality of DS processing modules. 2.The method of claim 1, wherein the access request comprises one of moreof: a request to store an encoded data slice; a request to delete theencoded data slice; a request to list the encoded data slice; and arequest to retrieve the encoded data slice.
 3. The method of claim 1,wherein the selecting the one of the plurality of DS processing modulesis based on one or more of: a query; a slice name associated with theencoded data slice; a vault identifier; a DSN memory identifier; a listof DS processing module identifiers; a DS processing module assignmentlist; a DS processing module performance indicator; a DS processingmodule capability indicator; and a last utilized DS processing moduleidentifier.
 4. The method of claim 1, wherein the response furthercomprises one of: an active master access indicator; a master DSprocessing module identifier; a proxy access indicator; and a rejectionmessage.
 5. The method of claim 1 further comprises: when the responseto the access request does not include an access indication: receivingan identity of the another one of the plurality of DS processing modulesin the response; and selecting the another one of the plurality of DSprocessing modules.
 6. A method comprises: receiving, from a userdevice, an access request to a dispersed storage network (DSN) memory;determining responsibility for the access request; and when theresponsibility is a proxy dispersed storage (DS) processing modulefunction: identifying a master DS processing module; and performing aproxy function related to the access request on behalf of the userdevice with the master DS processing module.
 7. The method of claim 6further comprises: when the responsibility is no responsibility:ignoring the access request; or sending a rejection message.
 8. Themethod of claim 6 further comprises: when the responsibility is aredirection function, sending a message to the user device thatidentifies the master DS processing module.
 9. The method of claim 6,wherein the determining the responsibility further comprises at leastone of: obtaining a master DS processing module indicator; obtaining aproxy access indicator; sending a query message; interpreting a slicename associated with the encoded data slice; interpreting a user deviceidentifier; interpreting a vault identifier; interpreting a DSN memoryidentifier; interpreting a list of DS processing module identifiers;interpreting a DS processing module assignment list; interpreting a DSprocessing module performance indicator; and interpreting a DSprocessing module capability indicator.
 10. The method of claim 6,wherein the identifying the master DS processing module comprises atleast one of: obtaining a master DS processing module indicator; sendinga query message; interpreting a slice name associated with the encodeddata slice; interpreting a vault identifier; interpreting a DSN memoryidentifier; interpreting a list of DS processing module identifiers;accessing a DS processing module assignment list; interpreting a DSprocessing module performance indicator; interpreting a DS processingmodule capability indicator; and interpreting a last utilized DSprocessing module identifier.
 11. The method of claim 6, wherein theproxy function comprises one or more of: forwarding the access requestto the master DS processing module; receiving a response from the masterDS processing module; and forwarding the response to the user device.12. A computer comprises: an interface; and a processing module operableto: select one of a plurality of dispersed storage (DS) processingmodules for facilitating access to a dispersed storage network (DSN)memory; send, via the interface, a DSN memory access request to the oneof the plurality of DS processing modules; select another one of theplurality of DS processing modules when no response is received within agiven time frame or when the response to the access request does notinclude an access indication; and send, via the interface, the DSNmemory access request to the another one of the plurality of DSprocessing modules.
 13. The computer of claim 12, wherein the accessrequest comprises one of more of: a request to store an encoded dataslice; a request to delete the encoded data slice; a request to list theencoded data slice; and a request to retrieve the encoded data slice.14. The computer of claim 12, wherein the processing module furtherfunctions to select the one of the plurality of DS processing modulesbased on one or more of: a query; a slice name associated with theencoded data slice; a vault identifier; a DSN memory identifier; a listof DS processing module identifiers; a DS processing module assignmentlist; a DS processing module performance indicator; a DS processingmodule capability indicator; and a last utilized DS processing moduleidentifier.
 15. The computer of claim 12, wherein the response furthercomprises one of: an active master access indicator; a master DSprocessing module identifier; a proxy access indicator; and a rejectionmessage.
 16. The computer of claim 12, wherein the processing modulefurther functions to: when the response to the access request does notinclude an access indication: receive, via the interface, an identity ofthe another one of the plurality of DS processing modules in theresponse; and select the another one of the plurality of DS processingmodules.
 17. A computer comprises: an interface; and a processing moduleoperable to: receive, from a user device via the interface, an accessrequest to a dispersed storage network (DSN) memory; determineresponsibility for the access request; and when the responsibility is aproxy dispersed storage (DS) processing module function: identify amaster DS processing module; and perform a proxy function related to theaccess request on behalf of the user device with the master DSprocessing module.
 18. The computer of claim 17, wherein the processingmodule further functions to: ignore the access request; or send, via theinterface, a rejection message, when the responsibility is noresponsibility.
 19. The computer of claim 17, wherein the processingmodule further functions to: send, via the interface, a message to theuser device that identifies the master DS processing module when theresponsibility is a redirection function.
 20. The computer of claim 17,wherein the processing module further functions to determine theresponsibility by at least one of: obtaining a master DS processingmodule indicator; obtaining a proxy access indicator; sending, via theinterface, a query message; interpreting a slice name associated withthe encoded data slice; interpreting a user device identifier;interpreting a vault identifier; interpreting a DSN memory identifier;interpreting a list of DS processing module identifiers; interpreting aDS processing module assignment list; interpreting a DS processingmodule performance indicator; and interpreting a DS processing modulecapability indicator.
 21. The computer of claim 17, wherein theprocessing module further functions to identify the master DS processingmodule by at least one of: obtaining a master DS processing moduleindicator; sending, via the interface, a query message; interpreting aslice name associated with the encoded data slice; interpreting a vaultidentifier; interpreting a DSN memory identifier; interpreting a list ofDS processing module identifiers; accessing a DS processing moduleassignment list; interpreting a DS processing module performanceindicator; interpreting a DS processing module capability indicator; andinterpreting a last utilized DS processing module identifier.
 22. Thecomputer of claim 17, wherein the proxy function comprises one or moreof: forwarding, via the interface, the access request to the master DSprocessing module; receiving, via the interface, a response from themaster DS processing module; and forwarding, via the interface, theresponse to the user device.